The invention provides a lightweight and multilayered composite sound isolation and heat insulation material. The lightweight and multilayered composite sound isolation and heat insulation material is prepared by carrying out alternate multilayered compounding on a high molecular material A and a high molecular material B, wherein the total number of layers of the lightweight and multilayered composite sound isolation and heat insulation material is 2n and n is larger than or equal to 2; the high molecular material A is filled with hollow glass microspheres; the high molecular material B is not filled with the hollow glass microspheres; and the density ratio of the high molecular material B to the high molecular material A is more than 1.5 and the modulus ratio is more than 1.2. The material combines the advantages of a formula design and a structure design very well, so that the material has a very good sound isolation performance and relatively small density, and also has a good heat insulation performance, and good toughness, high strength, environment friendliness and no toxin. A preparation method is simple and the technical problems that a preparation process for preparing a lightweight and multilayered sound isolation material by a traditional foaming process is complicated, a layer interface is not controllable and layer crossing is likely to occur are solved.